Ball grinding-mill.



0. E. WY MANI BALL GRINDING MILL. APPLICATION FILED APR. 27, 1908.

91 0,76 1 Patented Jan. 26,' 1909.

2 SHEETSS.HEET 1.

' c. E. wmm. BALL GRINDING MILL.

APPLICATION FILED APR. 21, 190B- Patented- Jan. 26, 1909.

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42 43 40f .29 JJ W5 J9 26 UNITED STATES CHARLES E. W'YMAN,

OF PEKIN, INDIANA.

BALL GRINDING-WILL.

Specification of Letters Patent.

Patented Jan. 26, 1909.

Application filed April 27, 1908. Serial No. 429,458.

To all whom it may concern:

Be it known that I, CHARLES E. W YMAN,a citizen of the United States, residing at Pekin, in the county of IVashington and State of Indiana, have invented a new and useful Bali Grinding-Mill, of which the fol lowing is a specification.

This invention relates to ball grinding mills, with special reference to the type known as ball and drum.

One object of the invention is to provide an improved general construction.

Another object of the invention is to provide an improved means for adjusting the pressure between the grinding elements in order to obtain a greater degree of fineness with the ground material.

The invention consists, substantially, in a conoidal interior portion made up of separate elements, a hollow conoidal exterior portion, and suitable balls between said portions, in combination with certain driving and adjusting means.

The invention further consists in certain novel combination of parts and arrangement of details hereinafter fully described, illustrated in the accompanying drawings, and specifically set forth in the claims.

In the accompanying drawings like characters of reference indicate like parts in the several views.

Figure 1 is a side elevation of a mill constructed in accordance with the present invention. Fig. 2 is a plan view of such mill. Fig. 3 is a transverse vertical section through Fig. 2. Fig. 4 is a detail view of the adjusting means on one of the exterior grinding elements. Fig. 5 is a detail of the means whereby the casing is attached to the exterior element.

As constructed in accordance with this invention the ball mill is provided with a base plate 10 having an annular ring or flange 11 extending upward therefrom. The base plate 10 is further provided with a centrallydisposed opening 12 and a laterally-disposed opening 13. Adjacent the laterally-disposed opening is a chute 14 for the purpose of conveying away the material which has been ground.

Mounted upon the base plate 10 is a grinding element 15 forming a part of the interior grinding drum. This grinding element is an nular in form and is rectangular in cross section in the preferred construction. Upon the grinding element 15 is a second grinding element 16 of smaller diameter than the firstmentioned element and above the second element 16 is another element 17. It is ob vious that these elements may be increased in number if desired, but the conoidal formation is kept throughout whatever the number may be. Each of the conoidal elements above the element 15 is provided with an annular lip 18 extending around the base in such manner as to fit in the open portion of the element immediately below. These lips thus form a secure lock and hold said elements in proper relative position. Exterior of these elements are other elements 19 20 and 21 forming a hollow conoidal exterior drum. These elements are spaced from the interior element and balls 22, 23 and 24 are held between the interior and exterior drum, the elements of the interior and exterior drums being provided with ball races, as indicated at 25, between which the balls 22-, 23 and 24 are held to move. These ball races are preferably made so as to closely conform to the contour of the balls. In the preferred form of construction the balls decrease in size from the top down, as clearly shown in Fig. 3.

The element 17 is provided above its ball race with a spreader of conoidal form, as indicated at 26.

In order to provide a means for driving the various elements there is provided a casing 27 having a pulley 28 formed thereon arranged to receive a belt. This casing is attached to the upper element 19 by bolts 29 shown best in Fig. 5. In order to drive the lower element the casing 27 is provided with interior ribs 30, shown clearly in Fig. 3. The ribs 30 fit in suitable slots cut in the exterior of the elements 20 and 21. The ribs 30 and the slots above referred to thus form a drivingconnection between the elements and the casing.

In order to give the right degree of pressure to the separate elements, the elements 20 and 21 are slidably mounted on the ribs, and a suitable compressing device is provided on the casing by which the position of the ele ments may be varied with relation to said casing. This compressing device in its preferred form consists of a stud bolt 31 tapped into the casing, and upon this stud bolt is slidably mounted a plate 32 from which depends a pair of arms 38 fixed tightly to the elements which it is desired to adjust. Up on the upper end of the stud bolt 31 is held a nut 34, and between this nut 34 and the plate 32 is a spring 35. It will now be plain that by adjustment of the nut 34 the plates 32 will be pressed downward with varying tension and thus afiect the elements to which the members 33 are attached. By means of the spring 35 slight relative movement of the element is permitted. It is obvious that this means is only for the adjustment of the lower exterior elements, and that in order to vary the pressure there must be some means provided for holding the upper exterior element in its proper position. In order to provide for this there is a plate 36 held beneath the base platelO. Passed through a suitable opening in the plate 36 and through the center of the elements forming the interior grinding drum is a bolt 37. Mounted above the exterior element on this bolt is a collar 33 provided with arms 39, each of which carries a roller 40 which bears against the upper exterior element, as clearly shown in Fig. 3. The upper end of the bolt 37 is threaded, as at 41, and is provided with a handled nut 42. Between the nut 42 and the collar 38 is a spring 43. This spring is of sufficient strength to overcome any ordinary upward tendency developed in the springs 35. It will be observed that by the bolts 37 and the devices connected therewith, the outer grinding drum may be adjusted as a whole, while, by the bolts 31 and the parts connected thereto, the various elements of said drum may be adjusted independently.

In order to prevent lateral movement of the lower part of the exterior drum and the casing, there is provided at spaced intervals around the bottom of said casing a plurality of guide rollers 44 suitably mounted in brackets 45.

Within the casing 27 there is mounted a blade 46 at the lower part thereof, said blade being arranged to carry the ground material to the chute 1 4.

It is to be observed that the interior and exterior drums are so spaced and arranged as to provide passages 47 and 48 therebetween. These passages, it will be noted, are arranged to deposit the partially ground. material on the interior of the ball races, as clearly indicated in Fig. 3.

In the operation of the device the unground materials are forced into the space around the upper end of the element 17, being spread by means of the spreader 26. This material is then partially ground by means of the balls 22, passes down the passage 47 and is further ground by the balls 23, passes down through the passage 48, and is finally ground by the balls 24. After this final grinding the material passes into the space between the element 16 and the casing 22 and is swept around in said space by blades 46 until it reaches the chute 14, down which it falls into any suitable receptacle that may be provided.

What is claimed is 1. In a ball mill, an interior grinding drum, a revoluble casing, an exterior grinding drum comprising an annular die immediately attached to said casing, another annular die rotatable with but slidable longitudinally of said casing, means to adjust the pressure between the first mentioned exterior die and the interior drum, and separate means to adjust the pressure between the other exterior die and the interior drum.

2. In a ball mill, an interior grinding drum, a revoluble casing, an exterior grinding drum comprising an annular die immediately attached to said casing at the top thereof, another annular die rotatable with but slidable longitudinally of said casing held beneath the first-mentioned die, means to adjust the pressure between the first mentioned die and the interior drum comprising a bolt extending through said interior drum, a collar provided with arms held upon said bolt at the upper end thereof, rollers mounted upon said arms and adapted to bear against said first-mentioned die, a handled nut mounted on said bolt above said collar, and a spring held between said nut and collar, and separate means to adjust the pressure between the exterior die and the exterior drum, comprising a plurality of bolts attached to said casing, yokes carried on said bolts, nuts mounted on said bolts above said yokes, and springs between said nuts and said yokes, said yokes being rigidly attached to the said die.

3. In a grinding mill, an interior grinding drum, an exterior grinding drum, grinding elements interposed between the two drums, a casing surrounding the drums, said casing being formed with a flange, a plate, arms carried by the plate and extending through the flange of the casing and bearing against an element of the exterior drum, a bolt passed through the plate and threaded into the said flange, and a spring upon the bolt bearing against the plate to hold the arms yieldably against the said element of the exterior drum, to exert a constant tension against the same.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

CHARLES E. WYMAN.

Witnesses:

ASA ELLIOTT, FRANK S. HoUsToN. 

